The present invention is related to a coating composed of an optically effective layer system, for glass and/or plastic substrate, whereby the layer system has a high anti-reflection effect. More specifically the invention related to multi-layer of metal films which has high scratch resistance.
U.S. Pat. No. 4,921,760, whose disclosure is an multi-layer anti-reflection coating (3-5 layer) with excellent adhesion between CeO.sub.2 layer and synthetic resin. The layer system including CeO.sub.2, Al.sub.2 O.sub.3,ZrO.sub.2,SiO.sub.2,TiO.sub.2 and Ta.sub.2 O.sub.5. All the thin films of the layer system are oxide materials.
U.S. Pat. No. 5,105,310, whose disclosure is an multi-layer anti-reflection coating designed for deposition in in-line coating matching by reactive sputtering. The layer system including TiO.sub.2, SiO.sub.2, ZnO, ZrO.sub.2 and Ta.sub.2 O.sub.5. All the thin films of the layer system are oxide material.
U.S. Pat. No. 5,091,244 and 5,407,733, disclosed a new type electric conductive light-attenuating anti-reflection coating. The major claim is an article comprising of nitrides of certain transition metal to provided an electrically-conductive, light-attenuating, anti-refection surfaces. The layer systems including TiN, NbN, SnO.sub.2, SiO.sub.2, Al.sub.2 O.sub.3 and Nb.sub.2 O.sub.5. The thin films of the layer system are nitride and oxide materials.
U.S. Pat. No. 4,196,246, 5,170,291 and 5,147,125 whose disclosures are a serious anti-reflection coating on different substrate by using different process. The layer systems including TiO.sub.2, SiO.sub.2, ZnO, Al.sub.2 O.sub.3, Bi.sub.2 O.sub.3, ZnS and MgF.sub.2. All the thin films of those layer systems are compose materials of oxide, sulfide and fluoride.
U.S. Pat. No. 5,216,542 whose disclosure is a five layer coating with high anti-reflection effect. The process use an adhesive layer of Ni, Cr or NiCr metal with a thickness about 1 nm (nanometer). Other four layers are compose of SnO.sub.2, ZrO.sub.2, ZnO, Ta.sub.2 O.sub.5, NiO, CrO.sub.2, TiO.sub.2, Sb.sub.2 O.sub.3, In.sub.2 O.sub.3, Al.sub.2 O.sub.3 SiO.sub.2, TiN and ZrN.
U.S. Pat. No. 5,541,770 whose disclosure is a light attenuating anti-reflection coating including electrically conductive layers. It is a four or five layer system. A light absorption high refractive index metal such as Cr, Mo and W was used as a optically effective thin film in the layer system. The other three or four layers are TiO.sub.2, ITO, Al.sub.2 O.sub.3, SiO.sub.2 and TiN. The patent shows that the majority materials of the layer system are oxide and nitride, only one metal film was used as an optical effective thin film in the anti-reflection coating.
The above description shows clearly that oxide and nitride are the dominate materials of the layer system for a typical and traditional anti-reflection coating.